Hello again , AgX , You are right , I have contacted with a sculptor and he said I have to come his place to learn to mix correct clay. I think I will go to one of art school to get help from them. May be I could get a life copy of my hand and work around it. I learned from ergonomy journals that the real trick is to create a form where your hand muscles grip but apply the least pressure and strain to your muscles.
Well , I think these handles made by very talented artists or drawing guys. You can draw 3 views of your desired handle and load to computer and it forms the correct 3d handle from 3 or more drawings. Well , I could produce one with 3d printer also
Sugru is polymer plastic and I dont feel about it well. I want wood , clay , or drawing to start to work.